IMHO you don't need a plunge router for the job, if you already have a fixed base router. If you don't have any type of router then get a fixed base one and a jig saw, that way you'll be able to get the job done, plus have both tools for the future.
Drill starter holes at the edge of where the hole will be and then use the jig saw to rough cut the hole. Then use the router with a flush trim bit and/or a template made from hardboard to finish the hole.
A plunge router is kind of unwieldly if your not used to handling it.
Good router brands IMHO are Porter Cable, Bosch and Makita. If all you are going to do with it is make stuff for your CP and cab, then you won't need a bells and whistles one or a very powerful one, no more than a couple HP. Router bits are fairly expensive so get a simple quality router and then get some good bits to go with it (make sure you get the right size shank on the router bits for your router). If you absolutely have to have a plunge router, then get a kit with the router motor and both a fixed and plunge base.
Honestly, I only ever use my plunge router for inlay stuff and making signs.
Hope this helps.